Keyword Research Capabilities
SEMrush is often considered superior for keyword research intent data and PPC analysis. Ahrefs excels in UI simplicity and estimating traffic potential across the entire SERP.
Backlink Index
Ahrefs historically had the fastest and most comprehensive backlink crawler. SEMrush has closed the gap significantly in recent years. Both are essential for checking a competitor's link profile.
Site Audit Tools
SEMrush’s site audit tool is incredibly detailed and integrates beautifully with Trello/Asana for task management. However, for a quick overarching health score, Ahrefs is very user-friendly.